Adjustable hollow milling-tool.



No. 759,425. PATENTED MAY 10, 1904.

A. ELMIGBR. ADJUSTABLE HOLLOW MILLING TOOL.

APPLICATION FILED AUG. 31, 1903.

N0 MODEL.

fz a a J- 9 L 2 L 1 vvfanesses.

, UNITED STATES ALBERT ELMIVGER, OF

Patented Ma 1o, 1904.

PATENT OFFICE. Y

DAYTON, KENTUCKY.

ADJUSTABLE HOLLOWMVILLING-TOOL,

SPECIFICATION forming part of Letters Patent No. 759,425, dated May 10, 1904. I

Application filed August 31, 1903.

To, all whont it may concern.-

Be it known that l, ALBERT ELMIG R, a citi- Zen of the United States, residingat Dayton, in the county of Campbell and State :of Kentucky, have invented certain new and useful Improvements in Adjustable Hollow Milling- Tools, of which the following is a specification.

My invention relates to adjustable hollow mills for turning or milling stems, rods, and the like on castings and facing the shoulders of same.

. The object of my invention is to provide a hollow mill which can be readily adjusted to compensate for wear and grinding of the blades and also to adjust the cutting edges of the blades toward or from each other, so that the stem may be turned to any size desired.

Another object is to save the expense of an entire new mill when any of the blades are broken by simply removing it and inserting a new blade, and so onas needed.

My invention consists in providing a hollow body having-a shank by which it is socured and held in the drill-press or lathe with reduced screw-threaded ends and with a plurality of longitudinal slots tapering ontheir bottoms from the shank to the other end, in blades each tapered upon its inner edge and adapted to take and fit into said slots, respectively, so that each blade will rest firmly upon the tapered bottom of the slot and the surface of the outer edge of each blade will be parallel with the outer surface of the body and also parallel with the inside cutting edges of the blades, said blades being notched to receive one of the nut-collars by which the blades are Serial'No. 171,385. (No model.)

perspective View of one of the cutting-blades. Fig.4 is an end view of the body with the nut-collar and blades removed. Fig. 5 is an end view of the body, showing the blades held in position by the nut-collar. Fig. 6 is a side view, partly broken away to show the interior threads and bevel of one of my nut-collars by which the blades are adjusted and held in position.

I preferably construct my improved milling-tool substantially as follows: The body 1 is formed cylindrical in shape and has a suitable shank 2 to secure it to the drill-press or other machine. Each end of the body 1 is reduced in size, and the reduced parts are provided with screw-threads 3, as shown in Fig. 1. Upon the outer surface of the body 1 I form a longitudinal slot 4 for each cutting-blade desired, any number of which may be used; but I prefer four blades. Said slots at the working end of the body extend entirelythrough the wall thereof to a point indicated by 5, Fig. 2, and from that point its bottom tapers upwardly the entire length of the body to the point marked 6. Each cutting-blade 7 (clearly shown in Fig. 3) is formed with its outer longitudinal edge 8 at right angles to the cutting end 9 audits inner edge 8 tapered to correspond with the bottom of the slot in order to keep the cutting edges 17 a on the inside parallel with each other and with the outer surface of thebody at all times. Said edge 8 is provided with notch 10, having its wall 11 and end 12 beveled to form bearings by which the blades are moved and held in position in the body by the nut-collars 13 and 14, each having interior screw-threads 15, which engage the threads 30f the body, and each having bevel 16, which engages the bevels 11 and 12 of the blades. The slots 4: are arranged, as shown in Fig. 4:, so that the blades when inserted, as shown in Fig. 5, will have their cutting-points 17 and cutting edges 18.0n a line extending radially from the center. Each nut-collar is provided with a hole 19 to provide for easy turning by means of the ordinary spanning-wrench.

body, so that the structure thus formed will be neater and stronger and also to allow the nut-collar to travel the full length of the thread upon the body.

The nut-collars 13 and 14 are made alike and are interchangeable.

The threads 3 at each end of the body are cut right hand, so that when one of the nutcollars is loosened and the other nut-collar turned in the same direction the blades will be adjusted and held firmly to the new position in the body.

The operation of my device is as follows: When it is desired to set the blades larger or farther apart, loosen the nut-collar at shank by turning the nut to the left, so that it will travel away from the bevel on the blades, then adjust the blades endwise by turning the nut-collar in notches 10 in the same direction, so that its bevel which bears against the bevels of the blades drives them endwise until locked against the bevel of the other nut-collar. In order to take one or more of the blades out of the body, turn the nut-collar in the notch 10 toward the left until almost or entirely released from the body, then slip the blades out separately beneath the nut-collar. To replace the blades, simply reverse the operation.

I prefer cutting the threads fine in order to secure a finer adjustment for the cutting edge. The variation in adjustment may be increased by enlarging the body 1 and giving the bottom of the slots a greater taper, or a similar result can be obtained by shortening the body of the mill.

It will be apparent from the foregoing that my improved device is capable of considerable modification without material departure from the scope and spirit of my invention, and for this reason I do not wish to be understood as limiting myself to the precise form and arrangement of the several parts herein set forth.

Having thus described my invention, I

- claim 1. In an adjustable hollow milling-tool, a body provided with a central opening adapted to receive the work to be operated on and having external longitudinal tapering slots, cutting-blades adapted to fit and be adjusted in said slots, each cutting-blade having its cutting edge adjacent said central opening and each blade also having a beveled notch in one edge to receive and engage a nut-collar, threads upon the body, a nut-collar also beveled to correspond with the said beveled notch to adjust and hold one end of each blade, and a nutcollar adapted to adjust and hold the opposite end of each blade said nut-collars engaging the threads of said body.

2. In an adjustable hollow milling-tool, a body provided with a central opening and having longitudinal tapering slots, cuttingblades adapted to fit in said slots, each blade having a notch upon its outer edge and the cutting edge arranged adjacent said central opening, threads upon each end of the body, and nut-collars adapted to be screwed thereon to engage, adjust and hold'the blades, substantially as set forth.

3. In an adjustable hollow milling-tool, a body provided with a central opening and having longitudinal external tapering slots, cutting-blades arranged in a circle around said opening to form a hollow milling-tool and adapted to fit in said slots and having their inner edges tapering to bring their outer edges parallel with each other and on the same cylindrical curve with the outer wall of the body at all times to render the tool more compact and permit the cutting edges of the blades to operate any desired distance within an opening large enough to receive the end of the tool, and means for adjusting and holding said blades in place.

4. In a milling-tool, a body provided with a central opening and having its ends reduced and screw-threaded, bevels upon the enlarged ends of the body and slanting upwardly away from the adjacent screw-threads and having longitudinal external slots each provided with a tapering bottom, detachable cutting-blades each having one edge notched near the cutting end with a bevel upon one wall of the notch and also beveled upon its opposite end and having its inner edge tapered to correspond with the bottom of the slot in order to keep the cutting edges on the inside parallel with each other and with the outer surface of the body at all times, and nut-collars adapted to screw on the reduced threaded ends of the body and each having its inner edge beveled to correspond with the bevel on the blades and also on the enlarged ends of the body.

5. In a hollow milling-tool, a detachable blade having its outer longitudinal edges at right angles to the cutting end of the blade, said blade being provided with a notch upon its outer edge, said notch having its Wall farthest from the cutting edge beveled and the end of the blade opposite the cutting end also beveled and having the inner longitudinal edge tapered.

6. In a milling-tool, a detachable blade having its outer edge at right angles to the cutting end and having a beveled notch near the cutting end, and its inner edge tapered from said end, the end opposite the cutting end being beveled, all substantially as and for the purposes set forth.

ALBERT ELMIGER.

I Witnesses:

G. C. GABEL, JAMES N. RAMSEY. 

